Abstract

Integration of multiple modalities like MRI with MEG/EEG plays a key role in localizing the neuronal activity with a given latency. This process is called co-registration. In this work we will discuss a three step procedure to prepare raw MRI data for co-registration. The primary requirement from the brain MR images is the extraction of the cortical surface of the brain. In order to perform cortical surface extraction, the acquired MR images are pre-processed to strip unwanted components, remove noise and avoid partial volume effect. This is achieved with the application of a skull stripping method based on hole-filling, dilation and erosion followed by anisotropic diffusion based filtering of the skull stripped images. Marker-based watershed segmentation is then performed to extract the cortical surface which can then be used for co-registration